282 PROCEEDINGS OF THE NATIONAL MUSEUM vol. i09 



Wing. — Pattern as figured, cross vein r-m pale (variety Jilariferus) 

 or dark on anterior end (typical form), vein R4+5 not infuscated in the 

 pale area over the apex of second radial cell, cell Mj with two pale 

 spots distal to the pale spot straddling vein M2. Macrotrichia sparse 

 on distal third of wing; costa extending to 0.67 (0.61-0.70, n = 35) of 

 distance to wing tip. Halter knob pale (typical form) or infuscated 

 (variety Jilariferus) . 



Abdomen. — Blackish, cerci pale. Spermathecae two, unequal, 

 pyriform, measuring 0.062 by 0.046 mm. and 0.053 by 0.039 mm. 



Male genitalia: Ninth tergum with small apicolateral processes. 

 Aedeagus with spherical, slender tip. Parameres with bases con- 

 nected by a short sclerotized loop, the apices at most with very few 

 microscopic branches. 



Distribution: Panama; Brazil; Colombia; Costa Rica; Ecuador; 

 French Guiana; Guatemala; Honduras: Mexico; Nicaragua; Suri- 

 nam; Trinidad; Venezuela. 



Panama records: 



Canal Zone: Balboa, Barro Colorado Island, Cabima (type locality). Camp 

 Butler, Cano Saddle, Fort Clayton, Fort Davis, Fort Gulick, Fort Kobbe 

 (horse trap), Fort Sherman, France Field (horse trap), Gamboa, Loma Boracho, 

 Madden Dam, Mindi Dairy, Mojinga Swamp. 



CniRiQuf Province: Gualaca, Lino, Pedregal, Rio Tabasara, Volcdn. 



CocL^ Province: El Valle, Rio Hato. 



Col6n Province: Pifia. 



Darien Province: El Real, Garachin6, Jaqu^, Punta Patifio. 



Herrera Province: Chitr^. 



Los Santos Province: Los Tablas, La Palma. 



PanamX Province: Arraijdn, Cerro Campana, La Jolla, Pacora, Pedregal, Isla 

 Taboga, Tocumen, Vique Cove. 



Veraguas Province: Rio Santa Marfa, Sapotilla. 



Discussion: This species is distinguished from its close relatives 

 by its smaller size, presence of mesonotal pattern, wings with the pale 

 markings sharp and rather extensive, vein R44.5 not infuscated on the 

 portion in the pale area at apex of second radial cell, and two pale 

 spots in cell Mi distal to the pale spot straddling vein M2. Species 

 with which it has been confused are: foxi Ortiz, which has a black spot 

 on vein R4+5 near the apex of the second radial cell; insignis Lutz, 

 which has vein R4+5 infuscated basally in the pale area over second 

 radial cell to the point where it turns abruptly forward to meet the 

 costa and only one pale spot in cell M, distal to the pale spot straddling 

 vein M2; and guttatus (Coquillett), which has no mesonotal pattern 

 and is larger. There is some variation in the wing markings of 

 diabolicus; rarely the distal spot in cell M, is obliterated, the cross- 

 vein r-m, which is normally pale, may be dark on the anterior end, 

 and the halter knob, which is normally infuscated, may be pale in the 



